1. Field of the Invention
The present invention relates to a waterproof connector suited for being disposed in, for example, an engine room and so on of vehicles.
2. Description of the Related Art
Automobiles are generally equipped with a variety of electronic devices. In this reason, a wiring harness is disposed or arranged in the automobiles so as to deliver or transfer a variety of signals, power and so on to the electronic devices disposed therein. The wiring harness generally has a plurality of electrical conduits and a connector connected to the afore-mentioned electrical conduits. The electrical conduit generally has a conductor as a core portion and a covering disposed on the conductor. The conductor may be formed of a plurality of wires or filaments. The covering is generally made of insulating synthetic polymer and so on.
The connector generally has a terminal fitting which is made of electrically-conductive metallic plate, and a connector housing for accommodating or receiving the afore-mentioned terminal fitting. The terminal fitting generally includes an electrical conduit-connecting portion and an electric contact portion. In further detail, the electrical conduit-connecting portion is coupled or connected to the terminal portion of the electrical conduit such that the core portion (i.e., the conductor) is connected thereto. The electrical contact portion is connected to a terminal fitting of a counterpart connector. The connector housing may be box-shaped, and may be also formed of insulating synthetic polymer material and so on. The connector housing has a terminal-accommodating chamber for accommodating or receiving the terminal fitting therein. The connector housing may be coupled to the counterpart connector.
In the afore-mentioned type of the wiring harness, the terminal fitting is coupled to the end portion of the electrical conduit, and is then leaded into the terminal-accommodating chamber. Thereafter, the connector is coupled to the counterpart connector. The wiring harness may be arranged in the vehicle such as automobiles so as to deliver or transfer the desired signal or power to a variety of electronic devices.
Furthermore, in the case of the afore-mentioned wiring harness, in order to prevent liquid such as water from adversely affecting the terminal fitting and so on, a waterproof-type connector has been employed as a connector. In further detail, when the terminal fitting is in contact with liquid such as water, it generally corrodes away. For example, Japanese Publication of Patent Application No. 2002-298656 discloses a conventional waterproof connector.
The waterproof connector as disclosed in Japanese Publication of Patent Application No. 2002-298656 can be kept liquid-tight by imbedding the end portion of the electrical conduit and a tube in the connector housing via a molding process. As such, between the electrical conduit and the connector housing, and between the tube and the connector housing can be kept liquid-tight. Moreover, due to the mold shrinkage, liquid-tightness can be kept between the tube and the end portion of the electrical conduit, and between the tube and the electrical conduit-connecting portion of the terminal fitting, respectively. Further, in this case, a counterpart connector which is coupled to or fit into the afore-mentioned connector may be also a waterproof connector. As such, when two of the waterproof connectors are coupled to each other, liquid such as water can be prevented from penetration into the terminal-accommodating chamber. Accordingly, the terminal fitting can substantially be avoided from being contact with liquid such as water or liquid adhesion.
Also, other type of waterproof connector is depicted in FIG. 6 as designated by a numeral 101. The waterproof connector 101 can be kept liquid-tight by injecting potting material 104 such as silicone rubber in a liquid state into a terminal-accommodating chamber 103, which receives or accommodates a terminal fitting 102 coupled to the end portion 106a of an electrical conduit 106. In this configuration, once the potting material 104 is cured, liquid-tightness can be kept inside the terminal-accommodating chamber 103. As such, liquid such as water can be prevented from penetrating into the terminal-accommodating chamber 103.
Meanwhile, in a case where the waterproof connector as disclosed in Japanese Publication of Patent Application No. 2002-298656 is arranged or disposed in the engine room of vehicles such as automobiles, the tube, the covering portion of the electrical conduit, and the terminal fitting are different in their coefficient of thermal expansion (CTE), and due to change in in-vehicle temperature the tube therefore has a tendency of peeling off or being delaminated from the covering and the terminal fitting. As a result, there is high probability that a gap or clearance is created between the tube and the covering of the electrical conduit, and/or between the tube and the terminal fitting. Also, due to the oscillation or vibration created while the automobile is traveling, a gap or clearance is inclined to be created or developed. Once the gap or clearance is created, liquid such as water can easily penetrate into the terminal-accommodating chamber via such a gap or clearance. In this case, liquid might adhere to the connection between the terminal fitting and the electrical conduit (i.e., the electrical conduit-connecting portion).
In addition, in the case of the waterproof connector as depicted in FIG. 6, the potting material 104 should be cured. Accordingly, a period of time should be required for the curing process. In this case, the product is required to remain in-line until the curing process is completed, thus causing the productivity of final product to decrease. Moreover, since the potting material 104 is injected into relatively extensive space within the terminal accommodating chamber 103, the potting material 104 should be employed in a large amount.
The present invention is provided to solve the afore-mentioned problems. In other words, in accordance with the present invention, there are provided a novel waterproof connector in which liquid such as water is securely prevented from adhering to the connection between the terminal fitting and the electrical conduit, and a novel method for producing the waterproof connector.